National Institute for Materials Science

Kyocera Corporation

Genki Yoshikawa

Gaku Imamura

Kota Shiba

Kosuke Minami

Takahiro Nemoto

Terunobu Akiyama

Takashi Washio

Masakazu Aono

Kyohei Kobayashi

Tomonobu Nakayama

Hisashi Sakai

Takanori Yasuda

Yusuke Yamauchi

Akiko Nakamura

Masanori Tohno

Hisami Kobayashi

Mitsuyoshi Ishida

Hideki Matsuzaka

Ryo Nakakubo

Ryo Tamura

Masaaki Matoba

Makito Nakatsu

Naoto Takeda

Vettiger Peter

Heinrich Rohrer

Peter Vettiger

Sebastian Gautsch

Frederic Loizeau

Hamish Hei-Man Yeung

Norihiro Suzuki

An object of the present invention is to make it possible to easily evaluate silage fermentation quality on site or the like. In one embodiment of the present invention, a gas generated from silage is applied to a surface stress sensor, and the amount of either one of organic acids and nitrogen-containing compounds contained in the silage is determined. The surface stress sensor can detect trace components in a gas by a simple device configuration and in simple procedures. Therefore, by utilizing the fact that relationship between the content of these components and the fermentation quality is known, the evaluation of fermentation quality can be easily realized by the above measurement.

Evaluation method and evaluation device for silage fermentation quality

An object of the present invention is to detect ammonia with high sensitivity and high selectivity using a nanomechanical sensor with a structure that is as simple as possible. A method for detecting ammonia according to an embodiment of the present invention comprises supplying a sample gas possibly containing ammonia to a nanomechanical sensor that detects a stress or a displacement using poly(methyl vinyl ether-alt-maleic anhydride) as a material of a receptor layer, and detecting presence or absence of ammonia or a content of ammonia in the sample gas based on an output signal from the nanomechanical sensor, in which the sample gas is a humidified sample gas with controlled relative humidity.

Humidification type highly-sensitive/highly-selective ammonia detection method and detection device using nanomechanical sensor

The present invention provides a method and a device for estimating a value to be estimated associated with a specimen, by performing machine learning of a relationship between a value of an estimation object and an output corresponding thereto, based on an output from a chemical sensor with regard to a plurality of specimens for which specific values to be estimated are known, and using the result of the mechanical learning to estimate a specific value to be estimated on the basis of an output from the chemical sensor with regard to a given unknown specimen.

Method and device for estimating value to be estimated associated with specimen

The present invention suppresses an adverse effect caused when an additional gas such as water vapor is mixed in a sample gas or the like that is subjected to gas measurement. In an embodiment of the present invention, in gas measurement for analyzing sensor output signals obtained by alternately supplying a sample gas and a reference gas to a sensor element while alternately switching between the sample gas and the reference gas, the sample gas and the reference gas pass through a humidity equilibration device partitioned by a water vapor permeable membrane, and then are supplied to the sensor element. As a result, since both gases have substantially the same value of humidity at the time of being supplied to the sensor element, influences of water vapor are substantially cancelled out in signals output from the sensor element by the alternate supply of the sample gas and the reference gas.

Measurement method and measurement device using gas sensor

Provided is a novel material analysis technique using a chemical sensor. By reversing the conventional approach, a material to be measured is provided as a receptor of the chemical sensor, and a response signal of the chemical sensor obtained by supplying a known gas or the like to the chemical sensor is obtained. From the response signal, it is possible to identify and distinguish the receptor material, and to obtain its composition and the like. By analyzing the response signal by means of a statistical or machine learning technique such as principal component analysis, linear discriminant analysis, or a support vector machine, the above-mentioned identification and the like can be performed with high accuracy.

Material analysis method and material analysis apparatus

The present invention provides a method for analyzing a liquid sample that solves a problem of a kinetically slow equilibrium at a liquid-solid interface, the problem occurring when liquid sample analysis is performed with a chemical sensor. In the method for analyzing a liquid sample according to an embodiment of the present invention, a component to be analyzed in a liquid sample is adsorbed on a receptor layer of a chemical sensor, one or more kinds of gases are then supplied to the chemical sensor, and a response thereof is measured. As a result, since a slow equilibrium at a liquid-solid interface is not used, a high-sensitivity measurement can be performed in a short time, and existing findings regarding analysis of gas samples on which much progress in research has been achieved can be used.

Method for analyzing liquid sample and apparatus

A method for cleaning a receptor layer of a surface stress sensor according to an embodiment of the present invention includes, in a surface stress sensor that detects a change in surface stress of a thin film, the change being caused by a receptor layer disposed on a surface of the thin film, causing at least a part of a surface region of the thin film to generate heat or supplying heat to the receptor layer from the outside of the surface stress sensor. This makes it possible to easily perform efficient cleaning of a surface stress sensor such as a sensor that performs detection using a piezoresistor while avoiding structural complications as much as possible.

Method for cleaning receptor layer of surface stress sensor

In an analysis of a fluid component using a nanomechanical sensor covered with a receptor, the same receptor is caused to express different response characteristics. In a measuring system of analyzing a response when a sample gas and a purge gas are supplied to a nanomechanical sensor while switching the sample gas and the purge gas, a gas (external gas) different from both gases is mixed into a gas channel and supplied to the sensor for measurement. Since a response characteristic of a receptor is modulated by mixing of the external gas, the object described above is achieved.

Receptor response modulation method, and measuring device using receptor response modulation

Provided is a novel analysis method which, when a chemical sensor is used to perform a measurement, makes it possible to identify a sample without controlling or monitoring a change in the time the sample is introduced. According to the present invention, a sample can be identified without knowing a change in the time the sample is introduced, by using a chemical sensor having a plurality of channels each having different characteristics to perform a measurement, and performing an analysis on the basis of responses obtained from each channel.

Method and device for identifying sample using chemical sensor

The invention provides: a gas sensor device that is capable of removing a component adsorbed on a gas sensor by relatively simple means and easily restoring a signal baseline of the gas sensor to a constant state; and a method for removing a gas component. The gas sensor device according to an embodiment of the invention includes a gas sensor and cleaning means that contains a liquid for cleaning the gas sensor. The gas sensor includes a sensor main body that is capable of detecting a characteristic parameter of a component present in a gas phase or a liquid phase, and a sensitive membrane that is coated on a surface of the sensor main body and is durable against the liquid.

Gas sensor device and method for removing gas component

Provided is a novel analysis method that enables identification of a sample even when any sample is introduced during measurement carried out by using a chemical sensor. An input in which the amount of an unknown sample changes over time is provided to the chemical sensor, a response which is from the chemical sensor and which changes over time is measured, a sensor function (transmission function) of the chemical sensor with respect to the unknown sample is calculated on the basis of the input and the response, and the unknown sample is identified on the basis of the sensor function of the chemical sensor with respect to the unknown sample.

Sample identification method based on chemical sensor measurement, sample identification device, and input parameter estimation method

The present invention provides a nanomechanical sensor in which a negative influence of water in a sample on measurement is suppressed. In an embodiment of the present invention, as a receptor material of the nanomechanical sensor, a low-hygroscopic material such as polysulfone, polycaprolactone, poly(vinylidene fluoride), or poly(4-methylstyrene) is used. According to this embodiment, a negative influence, such as saturation of a receptor layer by water in the sample, or masking of an output signal based on trace components by an output signal based on water contained in the sample in a large amount, can be suppressed.

Nanomechanical sensor receptor made of low-hygroscopic material and nanomechanical sensor using the same as receptor

Provided is a sensor which enables detection/identification of various types of fuels for automobiles by using simple devices. According to the present invention, high-octane gas, regular gas, diesel oil, heating oil, gasoline laced with heating oil, and the like can be clearly identified without using a large-scale analysis such as gas chromatography or mass spectroscopy by using a sensor having a structure in which a surface of a sensor body which detects a surface stress or the like is coated with particles modified with a hydrocarbon group such as an alkyl group.

Fuel oil identification sensor equipped with receptor layer composed of hydrocarbon-group-modified particles, and fuel oil identification method

According to improvement of the receptor layer of various sensors of the type for detecting physical parameters (for example, a surface stress sensor, QCM, and SPR), all of high sensitivity, selectivity, and durability are achieved simultaneously. A porous material or a particulate material, e.g., nanoparticles, is used in place of a uniform membrane which has been conventionally used as a receptor layer. Accordingly, the sensitivity can be controlled by changing the membrane thickness of the receptor layer, the selectivity can be controlled by changing a surface modifying group to be fixed on the porous material or particulate material, and the durability can be controlled by changing the composition and surface properties of the porous material or particulate material.

Sensor having porous material or particulate material as receptor layer

As a receptor layer, a film of a composite material of a base material such as a polymer and particles that adsorb an analyte is used. When the present invention is applied to a surface stress sensor or the like, the Young's modulus of the receptor layer, which significantly affects detection sensitivity, can be preset with a high degree of freedom, by independently selecting particles that adsorb a desired analyte and a base material that disperses said particles therein.

Growing community of inventors

Ibaraki, Japan

Genki Yoshikawa